Piston and connecting rod



Patented Oct. 12, 1948 PISTON AND CONNECTING non Gustaf A. Halfvarson, Springfield, Mass., assignor to Westinghouse Electric Corporation, East .Pittsburgh, Pa., a corporation oi Pennsylvania Application July 18, 1946, Serial No. 684,521

- vs Claims. 1

with the accompanying drawings forming a part of this application, in which:

Fig. 1 is a view, partly in cross section, of thejoint of this invention;

Fig. 2 is an elevation of the retainer of the joint;

Fig. 3 is a bottom view of the retainer shown in Fig. 2;

Fig. 4 is a view of the blank from which the retainer of Figs 2 and 3 is formed;

Fig. 5 is aview similar to Fig. 1 of a modification of this invention; and Y Fig. 6 is a plan view of the upper socket of the-joint shown in Fig. 5.

In the drawings, the reference numeral Ill designates a. piston having a dependent skirt l2. A spherical socket i4 is formed in the upper portion of the interior of the piston, which socket engages the upper part of a ball l6 of hardened steel secured to the upper end of a connecting rod I8. The lower end of the connecting rod l8 comprises a crankshaft bearing 2 I. The securement of the ball I 6 to the connecting rod l8 comprises a bore through the ball l6, which bore has .a body portion 20, a neck portion 22 above the body portion 20, and a. countersunk portion 24 above the neck portion 22. The upper end of the connecting rod It lies in the body portion of the bore and has an extension 25 which projects through the neck portion 22 and the countersunk portion 24. The portion projecting through the countersunk portion 24 is upset to ill] the countersunk portion 24 of the ball l6 and secure the ball IE to the connecting rod l8.

The lower portion of the ball i6 is engaged by a retainer 28. The retainer 28 is formed from a unitary sheet metal blank 30 (see Fig. 4) comprising a disk portion 3| having a. central opening 33 therein and four legs 34 at the periphery of the disk portion 3i. The central portion of -the blank 30 is depressed to form a socket 26.

The portion surrounding the socket 26 is turned downwardly to form a flange 32 to stiffen the upper portion of the retainer 28. The legs 34 continue in the same general curvature and, because of their curvature, provide a' slight springiness lengthwise of the legs. The retainer 28 is hardened after forming. The retainer 28 is secured in place in the piston ill by means of a split retainer ring 36 lying in a groove 38 near the lower edge of the piston skirt l2. The retainer ring 36 forms a shoulder on the interior of the skirt l2 and ispreferably located below the center of curvature of the socket l4 a distance equal to at least one half of the diameter of the piston l0.

In assembling the joint of this invention, the retainer 28 is slipped over the connecting rod IS, the ball is is then placed on the end of the connecting rod, and the connecting rod end upset into the countersunk portion 24 of the ball is. The ball i6 is then placed in the socket l4 and the retainer 28 pushed approximately into position. The retainer ring 36 is then forced upwardly into position in the groove 38'. The legs 34 of the retainer 28 are of such length that they are slightly compressed endwise when the split ring 36 is forced into position. The ball i6 is thus held between the two sockets I 4 and 26 by a. slight and resilient clamping pressure, the resilience being sumcient to take up the normal wear between the ball l6 and the two sockets l4 and 26 during use of the assembly. This joint is of use primarily in the compressor of a domestic refrigerator, the piston being about one inch in diameter and running at a, speed of about 1750 strokes per minute.

A modification of the joint of this invention is shown in Figs. 5 and 6, in which parts identical to those of the first-described modification are provided with the same reference numerals. In this modification, th upper socket 40 of the piston 42 is a hat-shaped stamping of sheet metal 44. Thebrim 46 of the stamping 44 engages a shoulder 48 formed in the skirt 50 of the piston 42.

It will be apparent from the above that this invention provides a joint between a connecting rod and a piston, which joint is formed of inexpensive sheet metal parts.

While I have shown my invention in several forms, it will be obvious to those skilled in the art that it is not so limited but is susceptible of I sphericalsocket in said piston, a shoulder on the interior of said skirt, said shoulder being locatedi below the center of curvature of said socket a distance equal to at least one-half the diameter 01' said piston, a connecting rod having a spherical head, the upper portion of said head lying in said socket, and a retainer comprising a unitary stamping of sheet metal, said stamping having a socket formed therein which engages the under side of said spherical head and an opening in the center of said socket through which opening said connecting rod extends, said socket being in'the form of a complete segment of a sphere, said stamping including a plurality or legs at the outer edge or said socket, said legs extending diagonally downwardly and resting on said shoulder. I 2. A piston and connecting rod. assembly as described in claim 1 in which said legs are resilient lengthwise and stressed to bias the socket portion 01' the retainer against said spherical head, said resiliency and stress being sufllcient to maintain a close working fit between the ball and said two sockets in spite of normal wear therebetween. Y

3. A piston and connecting rod. assembly as defined in claim 1 in which said legs are resilient lengthwise and in which the shoulder is insertable into its position in the piston skirt when the piston rod and retainer are in placein the piston, said insertion of said shoulder stressin said legs to bias said socket of the retainer and said spherical head of the connecting rod toward the socket in said piston. v I,

4. A piston and connecting rod assembly comprising a piston having a dependentskirt, a,

socket through which opening said connecting rod extends, a downwardly-turned flange portion piston, a connecting rod having a spherical head. I

spherical socket in said piston, a shoulder on the the center of curvature of aid socket a distance equal to at least one-half the diameter of said the upper portion of said'head lying in said socket, and a retainer comprising a stamping of sheet metal, said stamping having a socket formed therein which engages the-under side of said spherical head and an opening in the center of said socket through which opening said consupporting element being adapted to be moved upwardly into position after said connecting rod and retainer are in place and to engage the lower end of said legs during said upward movement to stress said legs endwise.

GUSTAF A. HALFVARSON,

REFERENCES crran The following references areof record in the file of this patent:

UNITED STATES PATENTS I Number Name Date 1,839,592 Reynolds Jan. 5, 1932 2,317,577 .Ackerman Apr. 27, 1943 2,089,614 Lordo Aug. 10, 1937 2,103,664 Smith Dec. 28, 1937 FOREIGN PATENTS Number Country Date 138,022 Great Britain June 29, 1920 434,957

Germany Oct. 4, 1926 

